On the multiple input multiple output capacity of Rician channels

We consider a wireless system with multiple antennas at both the transmitter and the receiver and operating in a Rician propagation environment. For fixed bandwidth and total transmitted power, the Rician channel matrix can be seen as the sum of two contributions. The first contribution is related to the deterministic component of the channel, which is given by the line-of-sight (LOS) path only. The second contribution denotes the stochastic component of the channel given by the Rayleigh fading paths, in which case the corresponding elements in the channel matrix are modeled as random variables. We focus on the averaged Rician channel capacity expression and its behavior according to the contribution of the deterministic and stochastic part of the channel. We derive an upper bound on the averaged Rician channel capacity and we show that a limit of this capacity is given by the sum of the capacities corresponding to the LOS and Rayleigh components when they are considered separately. Simulations results are given to support our claims.